Refrigerant compositions and methods of use

ABSTRACT

Compositions and methods are described for reducing flammability in a heating, ventilation, and air conditioning (HVAC) system having R32 refrigerant included in the refrigerant composition. Refrigerant compositions and methods of use are described which can be used for retrofitting, servicing, controlling flammability, improving performance, lubricant solubility and miscibility, and improving the safety of an HVAC system.

FIELD

The disclosure herein relates to refrigerant compositions, which can beused in, for example, refrigeration, air conditioning, and/or heat pumpsystems, which, for example, can be incorporated into a heating,ventilation, and air conditioning (HVAC) system or unit.

BACKGROUND

Concern about environment impact, e.g. ozone depletion, and the approvalof the Montreal Protocol resulted in a movement to replace ozonedepleting refrigerant compositions, such as for example,chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs). As aresult, replacement refrigerant compositions, such as for examplehydrofluorocarbon (HFC) refrigerants and hydrofluoroolefins (HFOs)refrigerants are commercialized. However, HFC refrigerants maycontribute to environment changes through their relatively largegreenhouse effect, e.g. having a relatively large global warmingpotential (GWP).

SUMMARY

Compositions and methods are described for reducing flammability in aheating, ventilation, and air conditioning (HVAC) system, for examplehaving R32 refrigerant included in the refrigerant composition.Refrigerant compositions and methods of use are described which can beused for retrofitting, servicing, controlling flammability, improvingperformance, lubricant solubility and miscibility, and improving thesafety of an HVAC system.

In an embodiment, a method of reducing flammability of a refrigerantcomposition in an HVAC system includes adding a first refrigerant intothe composition; adding a second refrigerant into the composition; andadding an amount of R125 refrigerant into the composition, the R125refrigerant is relatively less flammable than the first refrigerant andthe second refrigerant.

In an embodiment, the first refrigerant is R32 refrigerant and thesecond refrigerant is R1234yf refrigerant. In an embodiment, thepercentage by weight of the R32 refrigerant, the R125 refrigerant, andthe R1234yf refrigerant respectively ranges from 64.0 to 69.0, from 6.5to 7.5, and from 25.5 to 28.5.

In an embodiment, the amount of R125 refrigerant ranges from 5.5 percentby weight to 7.5 percent by weight.

In an embodiment, the amount of R125 is such that the global warmingpotential (GWP) of the refrigerant composition is below the GWP of R32refrigerant. In an embodiment, the refrigerant composition has a GWP of675 or less.

In an embodiment, adding the first refrigerant includes adding arefrigerant with a relatively high capacity compared to the secondrefrigerant and the R125 refrigerant. In an embodiment, the adding thesecond refrigerant includes adding a refrigerant with a relatively lowGWP compared to the first refrigerant and the R125 refrigerant.

In an embodiment, adding the first refrigerant, the second refrigerant,or the R125 refrigerant includes adding a refrigerant with a relativelyhigh lubricant solubility compared to the other two refrigerants, andadding a lubricant, the lubricant comprises POE, PVE, polyester, or acombination thereof.

In an embodiment, a method of reducing flammability of a refrigerantcomposition in an HVAC system includes selecting a suitable amount of anon-flammable refrigerant, selecting a suitable amount of one or morerefrigerants with a relatively low GWP compared to the non-flammablerefrigerant, where the one or more refrigerants is relatively flammablecompared to the non-flammable refrigerant, and mixing the non-flammablerefrigerant and the one or more refrigerants with a relatively low GWPto obtain a resulting refrigerant composition. The resulting refrigerantcomposition achieves a desired performance characteristic in the HVACsystem. The performance characteristic includes one or morethermodynamic properties of coefficient of performance (COP), capacity(CAP), a discharge temperature (Tdisch), or a combination thereof.

In an embodiment, a method of retrofitting a refrigerant composition inan HVAC system includes adding an amount of R125 refrigerant to aflammable refrigerant composition.

In an embodiment, the flammable refrigerant is one of a refrigerantblend of R32 refrigerant and R1234yf refrigerant respectively having apercentage by weight of 72.5 and 27.5, a refrigerant blend of R32refrigerant and R1234yf refrigerant respectively having a percentage byweight of 68.9 and 31.1, or a refrigerant blend of R32 refrigerant andR1234yf refrigerant respectively having a percentage by weight of 36 and64.

In an embodiment, the method of retrofitting further includes replacingan existing flammable refrigerant composition of the HVAC system withthe composition resulting from adding the amount of R125 refrigerant tothe flammable refrigerant composition.

In an embodiment, a method of servicing an HVAC system includes addingan amount of R125 refrigerant to a flammable refrigerant composition.

In an embodiment, a method of improving safety in an HVAC systemincludes adding an amount of R125 refrigerant to a flammable refrigerantcomposition.

In an embodiment, an HVAC system includes an operational refrigerantcomposition. The refrigerant composition includes R32 refrigerant, R125refrigerant, and R1234yf refrigerant. The percentage by weight of theR32 refrigerant, the R125 refrigerant, and the R1234yf refrigerantrespectively ranges from 64.0 to 69.0, from 6.5 to 7.5, and from 25.5 to28.5.

In an embodiment, a method of recycling R410A refrigerant from a HVACsystem includes removing existing R410A refrigerant from the HVACsystem, and adding a refrigerant composition to the HVAC system. Therefrigerant composition includes R32 refrigerant, R125 refrigerant, andR1234yf refrigerant. The percentage by weight of the R32 refrigerant,the R125 refrigerant, and the R1234yf refrigerant respectively rangesfrom 64.0 to 69.0, from 6.5 to 7.5, and from 25.5 to 28.5.

In an embodiment, a method of making a refrigerant composition includesselecting a suitable amount of a first refrigerant to addressflammability of the refrigerant composition, selecting a suitable amountof a second refrigerant to address GWP of the refrigerant composition,selecting a suitable amount of a third refrigerant to address capacityof the refrigerant composition, and mixing the first, second, and thirdrefrigerant.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1-11 illustrate characteristics of various embodiments ofrefrigerant compositions with R125.

FIG. 12 illustrates burning velocity (BV) of various refrigerantcompositions.

FIG. 13 illustrates a matrix showing lines of constant GWP and lines ofconstant BV.

FIG. 14 illustrates the matrix of FIG. 13 with further data points ofcomposition blends.

FIG. 15 illustrates the matrix of FIG. 13 showing lines of constant GWPand lines of constant BV.

FIGS. 16-19 each illustrate a matrix that can be used to selectrefrigerant compositions to achieve a desired set of properties.

DETAILED DESCRIPTION

Some relatively low GWP HFCs, (e.g. R32, R152a) and ultra-low GWP HFOs(e.g., R123yf, R1234ze(E)) are mildly flammable, which may prevent theuse of these low GWP refrigerants in a building HVAC system.

Embodiments as disclosed herein are directed to refrigerant compositionsand methods to reduce flammability of a refrigerant or a refrigerantcomposition, e.g. a refrigerant composition of low GWP HFC R32 and/or anultra-low GWP HFO R1234yf, by adding a non-flammable refrigerant (e.g.R125). The embodiments as disclosed herein may be used in refrigeration,air conditioning, and heat pump systems wherein the composition mayinclude a fluoroolefin and at least one other component. In someembodiments, the other component may be, for example, a secondfluoroolefin, hydrofluorocarbon (HFC), hydrocarbon, dimethyl ether,bis(trifluoromethyl) sulfide, CF₃I, or CO₂. The fluoroolefin compoundsused in the refrigerant compositions, e.g. HFC-1225ye, HFC-1234ze, andHFC-1234ye, may exist as different configurational isomers orstereoisomers. The embodiments disclosed herein are intended to includeall single configurational isomers, single stereoisomers or anycombination or mixture thereof. For instance,1,3,3,3-tetra-fluoropropene (HFC-1234ze) is meant to represent thecis-isomer, trans-isomer, or any combination or mixture of both isomersin any ratio. Another example is HFC-1225ye, by which is represented bythe cis-isomer, trans-isomer, or any combination or mixture of bothisomers in any ratio.

The embodiments as disclosed herein are directed to optimizeperformance, flammability and GWP (e.g. minimizing the flammability andGWP without sacrificing the performance of the refrigerant compositions)of the refrigerant compositions. In some embodiments, refrigerantcompositions including a flammable refrigerant composition including alow GWP HFC R32 and/or an ultra-low GWP HFO R1234yf, and a non-flammablerefrigerant R125 are disclosed. The refrigerant compositions may have alower flammability than the refrigerant including R32 and/or R1234yf, aGWP that is lower than R32, and similar performance characteristics asthe refrigerant composition of R32 and/or R1234yf. In some embodiments,the refrigerant compositions herein, when used in a HVAC system, mayhave a slightly lower compressor discharge temperature and temperatureglide than the refrigerant composition of R32 and/or R1234yf. In someembodiments, an operational pressure in a HVAC system using therefrigerant compositions as disclosed herein can be lower than a HVACsystem using R410A or R32. The refrigerant compositions disclosed hereinmay be used in a HVAC system to replace low GWP refrigerants, e.g. R410Aand R404A. The embodiments as disclosed herein may be used with otherflammable refrigerants to reduce flammability, other high GWPrefrigerants to reduce GWP, and/or other low capacity refrigerants toincrease capacity.

In some embodiments, a method of reducing flammability in a HVAC systemwith a non-flammable refrigerant (e.g. R125) is disclosed. In someembodiments, a method of retrofitting a HVAC system that has a flammablerefrigerant is disclosed. In some embodiments, a method of servicing aHVAC system to reduce flammability of the refrigerant in the HVAC systemis disclosed. In some embodiments, a method of improving safety of aHVAC system is disclosed. In some embodiments, a method of controlling aHVAC system to reduce flammability is disclosed. In some embodiments, amethod of additional control (e.g. control of the flammability) to theHVAC system is provided. In some embodiments, a method of improvinglubricant solubility, miscibility and/or performance in a HVAC system isprovided. In some embodiments, a method of recycling low GWP refrigerantR410A from a HVAC system is provided.

A method of reducing flammability of a refrigerant composition mayinclude adding a non-flammable refrigerant to the refrigerantcomposition. In one embodiment, flammability of a refrigerantcompositions including a low GWP HFCs, e.g. (R32, R152a) and/or aultra-low GWP HFOs (R123yf, R1234ze(E)) may be reduced by adding anon-flammable refrigerant (e.g. R125). In some embodiments, up to, at,or about 5.5% wt of R125 may be added into a refrigerant compositionincluding R32 and/or R1234yf, without the final GWP of the refrigerantcomposition exceeding the GWP of R32. In some embodiments, up to, at, orabout 7.5% wt of R125 may be added into a refrigerant compositionincluding R32 and/or R1234yf.

A method of reducing flammability of a refrigerant composition mayinclude adding a non-flammable refrigerant to a relatively flammablerefrigerant composition to reduce the flammability of the refrigerantcomposition. In some embodiments, the non-flammable refrigerant may beR125. In some embodiments, the amount of non-flammable refrigerant (e.g.R125) can be added up to, at, or about 7.5% wt. In some embodiments, therelatively flammable refrigerant composition may be 72.5% wt R32 and27.5% wt R1234yf, which is marketed as DR-5 by Dupont®, or may be 68.9%wt R32 and 31.1% wt R1234yf, which is marketed as DR-5A by Dupont®. Insome embodiments, the relatively flammable refrigerant can be othersuitable refrigerants, some of which can be found in U.S. Pat. No.7,914,698, which is incorporated by reference in its entirety herein. Insome embodiments, the relatively flammable refrigerant may be DR-5A(68.9% wt R32/31.1% wt R1234yf), DR-7 (36% wt R32/64% wt R1234yf), DR-4,or DR-3, which are marketed by Dupont®.

In some embodiments, the method of reducing flammability of arefrigerant composition may include balancing performancecharacteristics, flammability and GWP of the refrigerant composition(e.g. minimizing flammability, minimizing GWP and maximizing performancecharacteristics). In some embodiments, the method of reducingflammability of a refrigerant composition may include adding anon-flammable refrigerant (e.g. R125) to a relatively flammablerefrigerant composition so that the resulting refrigerant compositioncan match a design requirement (e.g. flammability of the refrigerant) ofa HVAC system.

A method of making a refrigerant for a HVAC system may include combiningsuitable amounts of a plurality of refrigerants, so that the resultingrefrigerant composition may match a design requirement (e.g. desiredproperties of the refrigerant) of a HVAC system. In some embodiments,the method of making a refrigerant for a HVAC system may includeselecting a non-flammable refrigerant (e.g. R125), and selecting one ormore refrigerants with a relatively low GWP (e.g. R32 and/or R1234yf),and mixing the non-flammable refrigerant and the one or morerefrigerants with a relatively low GWP. In some embodiments, the methodof making a refrigerant for a HVAC system may include blending asuitable amount of the non-flammable refrigerant and the one or morerefrigerants with a relatively low GWP, so that a desired performancecharacteristic of the resulting refrigerant composition in a HVAC systemmay be achieved. In some embodiments, the performance characteristic(e.g. thermodynamic properties) may be a coefficient of performance(COP), capacity (CAP), a compressor discharge temperature (Tdisch), or acombination of one or more of these characteristics. In someembodiments, the performance characteristic(s) of the resultingrefrigerant composition may be simulated and/or estimated by anExcel-based thermodynamic cycle calculation tool, such as for exampleNIST's REFPROP program. In some embodiments, a burn velocity (BV,cm/sec) may be simulated and/or estimated by an Excel-basedthermodynamic cycle calculation tool, such as for example NIST's REFPROPprogram.

In some embodiments, a refrigerant composition including R32 and R1234yfhas an increasing BV (e.g. flammability) may have a correlation with anincreasing % wt of R32 in the refrigerant composition. (See for exampleFIG. 12) In some embodiments, the flammability of the refrigerantcomposition can be reduced by adding R125 to the refrigerantcomposition.

In some embodiments, R125 may be added to DR-5 and/or DR-5A to reducethe flammability of DR-5 and/or DR-5A. In some embodiments, thecompositions of R32 and R1234yf can be adjusted to maintain a fixedcapacity as R125 is added. (See for example FIG. 1). In someembodiments, the R125 can be added in a suitable amount, so that theresulting refrigerant composition has a GWP that is the same or similarto R32. (See for example FIG. 1). The composition (e.g. % wt) of the R32and R1234yf in the resulting refrigerant composition may be furtheradjusted to meet performance characteristics. The resulting refrigerantcomposition can be used to replace R410A in a HVAC system. FIG. 1 isfurther described below.

In some embodiments, R125 may be added to DR-7 to reduce theflammability of DR-7. In some embodiments, the compositions of R32 andR1234yf can be adjusted to maintain a fixed capacity as R125 is added.(See for example FIG. 8). In some embodiments, the R125 can be added ina suitable amount, so that the resulting refrigerant composition has aGWP that is the same or similar to R32. (See for example FIG. 8). Thecomposition (e.g. % wt) of the R32 and R1234yf in the resultingrefrigerant composition may be further adjusted to meet performancecharacteristics. The resulting refrigerant composition can be used, forexample, to replace R404A in a HVAC system. FIG. 8 is further describedbelow.

A method of reducing flammability of a HVAC system may include addingnon-flammable refrigerant to a current refrigerant in the HVAC system.In some embodiments, R125 may be added to the current refrigerant in theHVAC system to reduce the flammability of the HVAC system. In someembodiments, the current refrigerant in the HVAC system may include R32.In some embodiments, the current refrigerant in the HVAC system may be72.5% wt R32 and 27.5% wt R1234yf, which is sold commercially as DR-5 byDupont®. In some embodiments, the current refrigerant can be othersuitable refrigerants, some of which can be found in U.S. Pat. No.7,914,698. In some embodiments, the amount of non-flammable refrigerant(e.g. R125) can be added up to or about 7.5% wt. It is to be noted thatthe methods as disclosed herein may be used to retrofit and/or servicean existing HVAC system having a flammable refrigerant. The methods asdisclose herein can also be used to increase safety in a HVAC system,e.g. reducing flammability of the HVAC system. The methods as discloseherein can also provide a method of controlling the HVAC system to, forexample, reduce flammability of the HVAC system.

In some embodiments, a refrigerant (e.g. R410A) in the HVAC system maybe replaced with the refrigerant compositions as disclosed herein,without the need of modifying the HVAC system (e.g. structures, circuitdesign, or control). In some embodiments, the refrigerant replaced (e.g.R410A) can be recycled to be used in another low GWP HVAC system.

Often replacement refrigerants are most useful if capable of being usedin the original refrigeration equipment designed for a differentrefrigerant. The refrigerant compositions disclosed herein may be usefulas replacements in original equipment.

In some embodiments, one or more refrigerant with different properties(e.g. flammability, lubricant solubility, miscibility, and performancecharacteristics) may be blended in a suitable amount, so that aresulting refrigerant composition may meet desired properties. In someembodiments, one or more non-flammable refrigerants can be added toachieve desired flammability in the resulting refrigerant. In someembodiments, one or more lubricant compatible (e.g. solvable)refrigerants can be used to achieve desired lubricant solubility in theresulting refrigerant.

A method of making a refrigerant composition with desired properties mayinclude blending a suitable amount of one or more refrigerants, each ofwhich may have different properties. The consideration of the desiredproperties of the refrigerant composition may include flammability, GWP,capacity, and/or lubricant solubility. In some embodiments, the methodmay include adding a refrigerant with a relatively low flammability(e.g. R125) to the refrigerant composition to reduce the flammability ofthe refrigerant composition. In some embodiments, the method may includeadding a refrigerant with a relatively low GWP (e.g. R1234yf) to therefrigerant composition to reduce the GWP of the refrigerantcomposition. In some embodiments, the method may include adding arefrigerant with a relatively high capacity (e.g. R32) to therefrigerant composition to increase the capacity of the refrigerantcomposition. In some embodiments, the method may include adding arefrigerant with a relatively high lubricant solubility (e.g. R125) tothe refrigerant composition to increase the lubricant solubility of therefrigerant composition. The lubricant may be, for example, POE, PV,polyester, or a combination thereof.

In some embodiments, the properties (e.g. GWP and/or capacity) of therefrigerant compositions herein may be made to resemble or match anexisting refrigerant (e.g. R410A, R22, and/or R404A), so that therefrigerant composition can be used to replace (e.g. drop in) theexisting refrigerant. In some embodiments, the refrigerant compositionmay be used to replace the existing refrigerant in a HVAC system. Thereplaced refrigerant may be reclaimed and/or repurposed to otherapplications. In some embodiments, the refrigerant composition may beused in a HVAC system with a screw compressor, a scroll compressor, areciprocating compressor or other suitable compressors.

Generally, a refrigerant composition as disclosed herein may includesuitable amounts of different refrigerants, each of which is selected tohelp achieve at least one property of the refrigerant composition. Insome embodiments, the refrigerant composition may include a suitableamount of a first refrigerant that is selected to address (e.g. reduce)flammability of the refrigerant composition, a suitable amount of asecond refrigerant that is selected to address (e.g. reduce) GWP of therefrigerant composition, and a suitable amount of a third refrigerantthat is selected to address (e.g. increase) capacity of the refrigerantcomposition. It is to be noted that in some embodiments, one refrigerantmay be able to address more than one property of the refrigerantcomposition.

Lower Alternatives to R410A and R404A with Improved Properties

Tests showing the impact of adding certain amounts of R125 refrigerant,for example to binary blends of R32 refrigerant and R1234yf refrigerantare described below with reference to FIGS. 1 to 11. Adding some amountof R125to blends, such as for example DR-5, DR-5A, and DR-7 (and DR-3and DR-4), can be beneficial in decreasing flammability of the blend(e.g. decreasing burn velocity). Some amount of the GWP may increase butmay still be maintained lower than R32 refrigerant. Results reported andillustrated in the graphs of FIGS. 1 to 11 are summarized below, andwere obtained using an Excel-based thermodynamic cycle calculation toolin relation to the known NIST's REFPROP program for estimatingthermodynamic properties of refrigerants.

1. Adding R125 to R410A and R410A Alternatives.

With reference to FIGS. 1 and 2, DR-5 (72.5% wt R32/27.5% wt R1234yf) byDuPont® had been previously proposed as an alternative to R410A, as ithad comparable performance relative to R410A, by way of having similarcapacity and coefficient of performance with a modest rise in compressordischarge temperature. For example, performance of a unitary airconditioning unit operating are predicted at conditions representingAHRI (Air-Conditioning, Heating, and Refrigeration Institute) standardAHRI-Std-210/240 “A” rating point as R125 is added.

FIG. 1 shows variation in performance as R125 is added to DR-5 blend atAHRI Std-210/240 “A” rating point. FIG. 2 shows the variation incomposition as R125 is added to DR-5 blend at AHRI Std 210/240 “A”rating point. In these simulations, the composition of R32/R1234yf isadjusted to maintain a fixed capacity as R125 is added. FIG. 2 showsthat up to 6.5% R125 can be added while keeping GWP less than R32 (677).FIG. 1 indicates that COP decreases very slightly as R125 is added,remaining about 1% higher than R410A. The capacity of DR-5 and theblends with R125 are lower than R410A by about 2%. Another benefit ofadding R125 is a slight reduction in compressor discharge temperature.

With reference to FIGS. 3 and 4, DR-5A (68% wt R32/32% wt R1234yf) byDuPont® was another potential R410A alternative. The higher R1234yfcontent lowers the capacity of this blend ˜2% relative to DR-5 and ˜4%relative to R410A, but also reduces the compressor discharge temperatureand can reduce the burning velocity. For example, performance of aunitary air conditioning unit operating are predicted at conditionsrepresenting AHRI (Air-Conditioning, Heating, and RefrigerationInstitute) standard AHRI-Std-210/240 “A” rating point as R125 is added.The predicted impacts on performance at the “A” rating condition areshown in FIGS. 3 and 4.

FIG. 3 shows the variation in performance as R125 is added to DR-5Ablend at AHRI Std-210/240 “A” rating point. FIG. 4 shows the variationin composition as R125 is added to DR-5A blend at AHRI Std-210/240 “A”rating point. In these simulations, the composition of R32/R1234yf isagain adjusted to maintain a fixed capacity as R125 is added. FIG. 4shows that up to 7.5% R125 can be added while keeping GWP less than R32(677). FIG. 3 indicates that COP decreases very slightly as R125 isadded, remaining about 1% higher than R410A. The capacity of DR-5A andthe blends with R125 are lower than R410A by about 4%. As above, addingR125 results in a slight reduction in compressor discharge temperature.

The small shortfall in capacity of DR-5 and DR-5A relative to R410A canbe made up by increasing the portion of R32 in the blend to 77.2% wt.FIGS. 5 and 6 show the predicted impact on performance of adding smallamounts of R125 to the starting blend R410A.

FIG. 5 shows the variation in performance as R125 is added to blendmatching R410A capacity at AHRI Std-210/240 “A” rating point. FIG. 6shows the variation in composition as R125 is added to blend matchingR410A capacity at AHRI Std-210/240 “A” rating point. In thesesimulations, the composition of R32/R1234yf is again adjusted tomaintain a fixed capacity as R125 is added. FIG. 6 shows that up to 5.5%R125 can be added to the starting R32/R1234yf blend while keeping GWPless than R32 (677). FIG. 5 indicates that COP decreases very slightlyas R125 is added, remaining about 1% higher than R410A and just slightlyabove R32. The blend is designed to match R410A's capacity rather thanaccept R32's ˜7.5% higher capacity. As above, adding R125 results in aslight reduction in compressor discharge temperature.

FIG. 7 shows variation in operating pressures as R125 is added to blendmatching R410A capacity at AHRI Std-210/240 “A” rating point. FIG. 7indicates that operating pressures increase as R125 is added to theR32/R1234yf blend. However, both the evaporator and condenser pressuresremain below the pressures for R410A and R32. The starting R32/R1234yfblends for R410A capacity matching, DR-5, and DR-5a exhibit relativelysmall temperature glides of ˜1.5° Fd, ˜2.1° Fd, and ˜2.7° Fd,respectively. Adding R125 to such blends tends to decrease thetemperature glide slightly (at or about 0.1. to at or about 0.2° Fd).

2. Adding R125 to R404A and R404A Alternatives.

DuPont proposed DR-7 (36% wt R32/64% wt R1234yf) as a low GWPalternative to R404A in refrigeration applications. DR-7 already has alower burning velocity than DR-5/5A because of its lower R32 content.However, addition of R125 can further reduce the flammability. FIGS. 8and 9 show the impact of adding R125 to DR-7 when operating at the“Transport #1” condition (−30° F. evaporator/114° F. condenser). Asabove, the R32/R1234yf composition is adjusted to maintain capacity ofDR-7.

FIG. 8 shows the variation in performance as R125 is added to DR-7 atthe “Transport #1” condition. FIG. 9 shows the variation in compositionas R125 is added to DR-7 at the “Transport #1” condition. In thesimulations, DR-7 is seen to offer ˜10% more capacity than R404A at thiscondition and ˜8% higher COP. Adding R125 results in a very slightdecrease in COP and compressor discharge temperature. One impact is thepotential reduction in flammability for a modest increase in GWP. DR-7has a condenser temperature glide of 9.2° Fd at this condition. AddingR125 causes the temperature glide to increase by ˜0.5° Fd at 5% R125.

By further reducing the R32 content, a blend can be made that matchesthe capacity of R404A at the “Transport #1” condition (29% wt R32/71% wtR1234yf). This can potentially lower flammability. COP is still 7%-8%higher than R404A, decreasing slightly as R125 is added. Only about 1.5%R125 is added to the blend before surpassing the GWP of DR-7. However,GWP for these R32/R1234yf/R125 blends are much lower than for R404A.FIG. 10 shows the variation in performance as R125 is added to a blendmatching R404A capacity at the “Transport #1” condition. FIG. 11 showsthe variation in composition as R125 is added to a blend matching R404Acapacity at the “Transport #1” condition.

FIGS. 13 to 19

FIG. 13 was developed to show a matrix 10 with contours of GWP andburning velocity as functions of R32, R1234yf and R125 concentration.Each side of the triangle 31, 32, 33 corresponds to a change of a GWP,BV and isentropic efficiency of a compressor respectively when a massfraction (e.g. % wt) of the refrigerants changes in a refrigerantcomposition. Each vertex 11, 12, 13 of the triangle corresponds to 100%wt of the refrigerant R125, R32 and R1234yf respectively.

The performance of R32/R125/R1234yf blends is predicted here using thesimple thermodynamic cycle model employed in earlier work. Keyassumptions are that the evaporator and condenser saturationtemperatures are the average of the bubble and dew point temperaturesand are the same for all refrigerants. Compressor isentropic efficiencyis also assumed to be the same for all refrigerants.

The matrix 10 shows lines of constant GWP and estimates of lines ofconstant burning velocity (BV) based on available data collected. Thediamond symbols are burning velocity data points from various sourcesthat calibrate the constant burning velocity curves. The matrix shows arange of compositions that could be useful as refrigerants with lowerGWP and lower flammability (burning velocity) for a range ofapplications for replacing R22, R407C, R404A, and R410A.

FIG. 14 shows a matrix 100, which is based on the matrix of FIG. 13 andwith the same sides and vertices of FIG. 13. The matrix is that same asthe matrix 10 of FIG. 13, except that the burning velocity data pointshave been removed, and the locations of certain composition blends areshown. R410A has been a commercial fluid for some time, being thereplacement for R22. R452A is a blend developed to replace R404A intransport refrigeration applications. DR-55 is a blend developed as areplacement for R410A and is one of the compositions herein. DR-55 isone preferred blend to replace R410A that has reducing flammabilitycompared to R32 while being a better match to R410A characteristics andhaving the same GWP as R32. DR-5, DR-5A (now R454B), DR-4, and DR-3 areR32/-R1234yf blends proposed by DuPont/Chemours. D2Y-60, D2Y-65, andD52Y are blends proposed by Daikin.

FIG. 15 shows a matrix 200 that is based from the matrix 10 of FIG. 13,and includes the same sides and vertices as in FIG. 13. FIG. 15 showsthe constant GWP lines and the constant burning velocity curves, andwhere the minimum ignition energy (MIE) is also shown with BV. MIE isthe amount of energy needed to initiate ignition of a flammable fluid.The MIE values shown on this and the previous matrices are estimatedfrom a known correlation with BV.

Referring to FIG. 16, a matrix 300 is disclosed which can be used in amethod of making a refrigerant composition with more than onerefrigerant to obtain a refrigerant composition with desired properties.The three exemplary refrigerants in the illustrated embodiment are R125,R1234yf and R32. Each side of the triangle 301, 302, 303 corresponds toa change of a GWP, BV and isentropic efficiency of a compressorrespectively when a mass fraction (e.g. % wt) of the refrigerantschanges in a refrigerant composition. Each vertex 311, 312, 313 of thetriangle corresponds to 100% wt of the refrigerant R125, R32 and R1234yfrespectively.

As illustrated, referring to side 301, a value of GWP increases in therefrigerant composition when the mass fraction of R1234yf decreases.Referring to side 302, a value of the BV decreases when the massfraction of R125 increases. Referring to side 303, a value of theisentropic efficiency increases when the mass fraction of R1234yfdecreases. Properties (e.g. GWP, BV and isentropic efficiency) of arefrigerant composition with a specific mass fraction of therefrigerants R1234yf, R32 and R125 can be estimated by using the matrix300.

In some embodiments, for example, a desired set of properties of auseful refrigerant composition may include a GWP that is no more than1500, BV that is no more than 5 cm/s, and a capacity that is no morethan 105% of the capacity of R410A and no less than 90% of the capacityof R22. Based on these properties, a useful range may be defined in thematrix 300. The refrigerant compositions in the useful range can satisfythe desired set of properties.

In some embodiments, for example, a more preferred set of properties ofa useful refrigerant composition may include a GWP that is no more than750, BV that is no more than 5 cm/s, and a capacity that is no more than105% of the capacity of R410A and no less than 90% of the capacity ofR22. Based on these properties, a preferred range may be defined withinthe useful range (e.g. the area defined by the solid lines) in thematrix 300. The refrigerant compositions in the preferred range cansatisfied the more preferred set of properties.

It is noted that the refrigerants R124, R1234yf and R32 are exemplary.Other suitable refrigerants may be used to address the flammability,capacity and/or GWP of the refrigerant composition. For example, anothersuitable non-flammable refrigerant can be used to reduce theflammability of the refrigerant composition. Another suitable low GWPrefrigerant can be used to reduce the GWP of the refrigerantcomposition. Another suitable high capacity refrigerant can be used toincrease the capacity of the refrigerant composition.

Based on the matrix 300, the refrigerant compositions may be furtherselected to replace specific refrigerants, such as for example, R404A,R410A, and R22. Generally, the capacity (e.g. in the form of isentropicefficiency of compressor) of these refrigerants may be used to define arefrigerant composition range in the matrix 300 that can be used toreplace these refrigerants.

It is noted that the capacity may be provided, for example, in ameasurement performed in a lab and/or in a computer based simulation.The capacity may be provided based on operation conditions provided inStandard for Performance Rating of Unitary Air-Conditioning & Air-sourceHeat Pump Equipment (e.g. Air-Conditioning, Heating and RefrigerationInstitute Standard (AHRI Std) 210/240).

The matrix 300 shows the range of compositions that produce capacitiessimilar to R410A (from 90% to 105%). The useful range is bounded at thetop by GWP=1500. The preferred range is bounded at the top by GWP=750.The composition of DR-55 was selected to have a burning velocity of 3cm/s and a GWP of 675. DR-55 produces a capacity about 2.5% less thanR410A, an acceptable compromise to achieve the lower burning velocity.

R32 is located at the lower right corner of the matrix with a burningvelocity of 6.7 cm/s and a GWP of 677. DR-55 is a significantly closermatch to R410A characteristics than R32.

Referring to FIG. 17, a method of making refrigerant a composition toreplace R410A using the matrix 400 is described and is based on thematrix 300 of FIG. 16, where the sides and vertices are the same as inFIG. 16. The capacity of the refrigerant compositions in the matrix 400may be matched to no less than 90% of the capacity of R410A (90% line inthe matrix 400) to no more than 105% of the capacity of R410A (105% linein the matrix 400). A useful range and a preferred range of therefrigerant compositions to replace R410A may be further defined in theuseful range and the preferred range as illustrated in FIG. 16 by the90% line and the 105% line, which are illustrated in FIG. 17 by thedarkened lines. The refrigerant compositions in the useful range in FIG.17 generally has a capacity that is no less than 90% of the capacity ofR410A and no more than 105% of the capacity of R410A, a GWP that is nomore than 1500, and BV that is lower than 5 cm/s. The refrigerantcompositions in the preferred range in FIG. 17 generally has a capacitythat is no less than 90% of the capacity of R410A and no more than 105%of the capacity of R410A, a GWP that is no more than 750, and BV that islower than 5 cm/s. Specific refrigerant compositions may also beselected in the matrix 400 based on, for example, a specific GWP, aspecific capacity and a specific BV. For example, the refrigerantcompositions having a GWP of about 675, 100% of the capacity of R410Aand a BV that is lower than 5 cm/s may be 74% wt of R32/5.5% wtR125/20.5% R1234yf, which is shown as the cross point of the line forGWP 675 and the line for 100% R410A capacity. Similarly, in some otherembodiments, a refrigerant composition with 98% of the capacity ofR410A, a GWP that is about 675 and a BV that is lower than 5 cm/s may be69% wt R32/6.5% wt R125/24.5% wt R1234yf. In some embodiments, arefrigerant composition with 96% of the capacity of R410A, a GWP that isabout 675 and a BV that is lower than 5 cm/s may be 65% wt R32/7.5% wtR125/28.5% wt R1234yf. In some embodiments, a refrigerant compositionwith 90% of the capacity of R410A, a GWP that is about 675 and a BV thatis lower than 5 cm/s may be 52% wt R32, 10% wt R125 and 38% wt R1234yf.

In FIG. 17, lines of constant capacity at 90%, 95%, 100%, and 105%relative to R410A are shown on the composition diagram (matrix). Theoperating conditions are taken as 115° F. (46.1° C.) average condensersaturation temperature with 15° F. (8.3° C.) of exit sub-cooling, 50° F.(10° C.) average evaporator saturation temperature with 20° F. (11.1°C.) of exit superheat, and a compressor isentropic efficiency of 0.70.These conditions are representative of operation at the AHRI Standard210/240 (AHRI-210/240, 2008) unitary air-conditioning “A Test” point.FIG. 17 shows that there is a wide range of compositions that can matchthe capacity of R410A within −10% to +5% while potentially havingburning velocities below 3 cm/s. The flammability of potential R410Areplacements may be reduced by adding R125 to R32/R1234yf blends up to achosen limit for GWP. The blend of 67% wt R32/7% wt R125/26% wt R1234yf,labelled DR-55, with a GWP of 675, burning velocity of 3.0 cm/s and97.3% of R410A capacity has been chosen for further evaluation here.Similarly, blends of R32 and R1234yf with R125 can be formulated toclosely match the characteristics of R404A and R22 with lowerflammability. See discussion of FIGS. 18 and 19.

The thermodynamic properties of DR-55, along with R410A and R32 arereported. For a given temperature, the pressure of DR-55 runs 5% lowerthan R410A and R32 runs 1% to 2% higher than R410A. DR-55 exhibits asmall temperature glide, ranging from 1.6° F. (0.9° C.) at −40° F. (−40°C.) to a maximum of 2.3° F. (1.3° C.) at 77° F. (25° C.).

Critical temperature and pressure of R410A, DR-55 and R32 are listed inTable 1. DR-55's critical temperature is much higher than R410A andslightly higher than R32. This provides extended high ambienttemperature operating range relative to R410A. The pressure andtemperature enthalpy domes are wider for DR-55 than for R410A, becauseof DR-55's higher R32 content. This can reduce the refrigerant mass flowrate needed to achieve a given capacity, potentially reducing pressuredrop through heat exchangers. Although DR-55 has an elevated compressordischarge temperature relative to R410A, it is substantially lower thanwith R32.

TABLE 1 Critical Properties of Refrigerants. R410A DR-55 R32 criticaltemperature 160.4/71.3 175.4/79.7 172.6/78.1 (° F./° C.) criticalpressure  711/4.90  803/5.53  839/5.78 (psia/MPa)

Referring to FIG. 18, a method of making a refrigerant composition toreplace R22 based on the matrix 500 is described and is based on thematrix 300 of FIG. 16, where the sides and vertices are the same as inFIG. 16. The capacity of the refrigerant compositions in the matrix 500may be matched to no less than 90% of the capacity of R22 (90% line inthe matrix 500) to no more than 110% of the capacity of R22 (110% linein the matrix 500). A useful range and a preferred range of therefrigerant compositions to replace R22 may be further defined in theuseful range and the preferred range as illustrated in FIG. 16 by the90% line and the 110% line, which are illustrated in FIG. 18 by darkenedlines. The refrigerant compositions in the useful range in FIG. 18generally has a capacity that is no less than 90% of the capacity of R22and no more than 110% of the capacity of R22, a GWP that is no more than1500, and BV that is lower than 5 cm/s. The refrigerant compositions inthe preferred range in FIG. 18 generally has a capacity that is no lessthan 90% of the capacity of R22 and no more than 110% of the capacity ofR22, a GWP that is no more than 750, and BV that is lower than 5 cm/s.Specific refrigerant compositions may also be selected in the matrix 500based on, for example, a specific GWP, a specific capacity and aspecific BV. For example, the refrigerant compositions having a GWP ofabout 675, 110% of the capacity of R22 and a BV that is lower than 5cm/s may be 28% wt of R32/15% wt R125/57% of R1234yf, which is shown asthe cross point of the line for GWP 675 and the line for 110% of thecapacity of R22. Similarly, in some other embodiments, a refrigerantcomposition with 100% of the capacity of R22, a GWP that is about 675and a BV that is lower than 5 cm/s may be 19.5% wt R32/17% wt R125/63.5%wt R1234yf. In some embodiments, a refrigerant composition with 90% ofthe capacity of R22, a GWP that is about 675 and a BV that is lower than5 cm/s may be 11.5% wt R32/19% wt R125/69.5% wt R1234yf.

The matrix 500 shows the range of compositions that produce capacitiessimilar to R22 (from 90% to 110%). The useful range is again bounded atthe top by GWP=1500. The preferred range is again bounded at the top byGWP=750. Note that D52Y is a close match to R22 characteristics with aGWP of 895 and a burning velocity estimated to be less than 1 cm/s.R407C has been used as a replacement for R22. New lower GWP replacementsfor R22 may also serve as replacements for R407C where R407C has alreadyby substituted for R22.

Referring to FIG. 19, a method of making refrigerant compositions toreplace R404A based on the matrix 600 is described, and is based on thematrix 300 of FIG. 16, where the sides and vertices are the same as inFIG. 16. The capacity of the refrigerant compositions in the matrix 600may be matched to no less than 90% of the capacity of R404A (90% line inthe matrix 600) to no more than 110% of the capacity of R404A (110% linein the matrix 600). A useful range and a preferred range of therefrigerant compositions to replace R404A may be further defined in theuseful range and the preferred range as illustrated in FIG. 16 by the90% line and the 110% line, which are illustrated in FIG. 19 by darkenedlines. The refrigerant compositions in the useful range in FIG. 19generally has a capacity that is no less than 90% of the capacity ofR404A and no more than 110% of the capacity of R404A, a GWP that is nomore than 1500, and BV that is lower than 5 cm/s. The refrigerantcompositions in the preferred range in FIG. 19 generally has a capacitythat is no less than 90% of the capacity of R404A and no more than 110%of the capacity of R404A, a GWP that is no more than 750, and BV that islower than 5 cm/s. Specific refrigerant compositions may also beselected in the matrix 600 based on, for example, a specific GWP, aspecific capacity and a specific BV. For example, the refrigerantcompositions having a GWP of about 675, 110% of the capacity of R404Aand a BV that is lower than 5 cm/s may be 31.5% wt of R32/14.5% wt ofR125/54% of R1234yf, which is shown as the cross point of the line forGWP 675 and the line for 110% of the capacity of R404A. Similarly, insome other embodiments, a refrigerant composition with 100% of thecapacity of R404A, a GWP that is about 675 and a BV that is lower than 5cm/s may be 24% wt R32/16% wt R125/60% wt R1234yf. In some embodiments,a refrigerant composition with 90% of the capacity of R404A, a GWP thatis about 675 and a BV that is lower than 5 cm/s may be 17% wt R32/17.5%wt R125/69.5% wt R1234yf.

The matrix 600 shows the range of compositions that produce capacitiessimilar to R404A (from 90% to 110%). The useful range is again boundedat the top by GWP=1500. The preferred range is again bounded at the topby GWP=750.

It is to be appreciated that other refrigerants may be used to achievethe desired properties as listed herein. It is also to be appreciatedthat the method described herein may be used to achieve other desiredproperties in the refrigerant compositions.

Generally, a method of making a refrigerant composition with a desiredset of properties may include determining the desired set of properties,and selecting at least one refrigerant for each of the properties in thedesired set of properties. The refrigerant(s) selected to exhibit thedesired property has a property value that is better than the propertyvalue of the desired property exhibited by the other refrigerants in thecomposition. The method may also include mixing the selectedrefrigerants in a suitable mass fraction so that the resultingrefrigerant composition has the desired set of properties. In someembodiments, a matrix can be made to represent a correlation of propertyvalue changes in response to mass fraction changes in the selectedrefrigerants. Suitable refrigerant composition ranges to achieve thedesired set of properties may be selected from the matrix by definingboundary property values in the matrix. The method disclosed herein canprovide flexibility in making a refrigerant to satisfy, for example,different design requirements.

Exemplary embodiments of refrigerant compositions as disclosed hereinare listed in the following Table 2.

TABLE 2 Composition (% by weight) GWP BV 50% R32/50% R125 1924 n/a 100%R32 ~677 6.7 R32/R125/R1234yf ~677 3.4 (74.0%/5.5%/20.5%) (e.g. 675)R32/R125/R1234yf ~677 3.1 (69.0%/6.5%/25.5%) (e.g. 673) R32/R125/R1234yf~677 3.0 (67.0%/7.0%/26.0%) R32/R125/R1234yf ~677 2.8 (64.0%/7.5%/28.5%)(e.g. 671) R32/R125/R1234yf ~750 2.6 (62.0%/10.5%/27.5%) (e.g. 753)R32/R125/R1234yf ~677 1.3 (20.0%/17.5%/62.5%) (e.g. 674)R32/R125/R1234yf ~750 1.1 (18.0%/20.0%/62.0%) (e.g. 756)

Table 2 illustrates simulation results of GWP and BV of variousrefrigerant compositions. As illustrated in Table 2, a refrigerantcomposition R32/R125 (50% wt/50% wt) has a GWP of 1924 is refrigerantR410A in some applications and can be compared to other refrigerantblends for potential replacement.

Refrigerant compositions of R32/R125/R1234yf (74.0% wt/5.5% wt/20.5%wt), R32/R125/R1234yf (69.0% wt/6.5% wt/25.5% wt), R32/R125/R1234yf(64.0% wt/7.5% wt/28.5% wt) and R32/R125/R1234yf (20.0% wt/17.5%wt/62.5% wt) may have a similar GWP as 100% wt R32 (e.g. 677), butincreasingly lower BV (e.g. lower flammability) respectively compared to100% wt R32 (e.g. 6.7). The refrigerant composition of R32/R125/R1234yf(62.0% wt/10.5% wt/27.5% wt), and R32/R125/R1234yf (18.0% wt/20.0%wt/62.0% wt) may have a slightly higher GWP (e.g. 750) compared to 100%wt R32, but a lower BV (e.g. <1 cm/s). The refrigerant compositionR32/R125/R1234yf (74.0% wt/5.5% wt/20.5% wt) may be used to replaceR410A in some applications. More preferred, the refrigerant compositionsR32/R125/R1234yf (69.0% wt/6.5% wt/25.5% wt) may be used to replaceR410A in some applications because, for example, a capacity of therefrigerant compositions may be similar to R410A. Even more preferred,any one or more of the refrigerant compositions R32/R125/R1234yf(67.0%/7.0%/26.0%) or R32/R125/R1234yf (64.0% wt/7.5% wt/28.5% wt) orR32/R125/R1234yf (62.0% wt/10.5% wt/27.5% wt) may be used to replaceR410A in some applications. The refrigerant compositionsR32/R125/R1234yf (20.0% wt/17.5% wt/62.5% wt) or R32/R125/R1234yf (18.0%wt/20.0% wt/62.0% wt) may be used to replace R22, R407C or R404A in someapplications, because, for example, a capacity of the refrigerantcompositions may be similar to R22, R407C or R404A.

Certain of the refrigerant compositions herein are non-azeotropiccompositions. A non-azeotropic composition may have certain advantagesover azeotropic or near azeotropic mixtures. A non-azeotropiccomposition is a mixture of two or more substances that behaves as amixture rather than a single substance. One way to characterize anon-azeotropic composition is that the vapor produced by partialevaporation or distillation of the liquid has a substantially differentcomposition as the liquid from which it was evaporated or distilled,that is, the admixture distills/refluxes with substantial compositionchange. Another way to characterize a non-azeotropic composition is thatthe bubble point vapor pressure and the dew point vapor pressure of thecomposition at a particular temperature are substantially different.Herein, a composition is non-azeotropic if, after 50 weight percent ofthe composition is removed, such as by evaporation or boiling off, thedifference in vapor pressure between the original composition and thecomposition remaining after 50 weight percent of the originalcomposition has been removed is greater than about 10 percent.

The refrigerant compositions may be prepared by any convenient method tocombine the desired amounts of the individual components. A preferredmethod is to weigh the desired component amounts and thereafter combinethe components in an appropriate vessel. Agitation may be used, ifdesired.

An alternative way for making refrigerant compositions may be a methodfor making a refrigerant blend composition, where the refrigerant blendcomposition includes a composition as disclosed herein. The method mayinclude (i) reclaiming a volume of one or more components of arefrigerant composition from at least one refrigerant container, (ii)removing impurities sufficiently to enable reuse of said one or more ofthe reclaimed components, (iii) and optionally, combining all or part ofsaid reclaimed volume of components with at least one additionalrefrigerant composition or component.

A refrigerant container may be any container in which is stored arefrigerant blend composition that has been used in a refrigerationapparatus, air-conditioning apparatus or heat pump apparatus. Therefrigerant container may be the refrigeration apparatus,air-conditioning apparatus or heat pump apparatus in which therefrigerant blend was used. Additionally, the refrigerant container maybe a storage container for collecting reclaimed refrigerant blendcomponents, including but not limited to pressurized gas cylinders.

Residual refrigerant means any amount of refrigerant blend orrefrigerant blend component that may be moved out of the refrigerantcontainer by any method known for transferring refrigerant blends orrefrigerant blend components.

Impurities may be any component that is in the refrigerant blend orrefrigerant blend component due to its use in a refrigeration apparatus,air-conditioning apparatus or heat pump apparatus. Such impuritiesinclude but are not limited to refrigeration lubricants, particulatesincluding but not limited to metal, metal salt or elastomer particles,that may have come out of the refrigeration apparatus, air-conditioningapparatus or heat pump apparatus, and any other contaminants that mayadversely affect the performance of the refrigerant blend composition.

Such impurities may be removed sufficiently to allow reuse of therefrigerant blend or refrigerant blend component without adverselyaffecting the performance or equipment within which the refrigerantblend or refrigerant blend component will be used.

It may be necessary to provide an additional refrigerant blend orrefrigerant blend component to the residual refrigerant blend orrefrigerant blend component in order to produce a composition that meetsthe specifications required for a given product. For instance, if arefrigerant blend has three components in a particular weight percentagerange, it may be necessary to add one or more of the components in agiven amount in order to restore the composition to within thespecification limits.

The refrigerant compositions herein may have low ozone depletionpotential and low global warming potential (GWP). Additionally, therefrigerant compositions may have global warming potentials that areless than many hydrofluorocarbon refrigerants currently in use. Oneaspect of the embodiments described herein is to provide a refrigerantwith a global warming potential of less than 1000. Another aspect of theembodiments herein is to reduce the net GWP of refrigerant mixtures byadding fluoroolefins to the refrigerant compositions.

It is to be noted that other components, e.g. lubricant or anotherrefrigerant, may be added to the refrigerant compositions as describedherein. The refrigerant compositions as described herein may alsoinclude impurities.

The refrigerant compositions may further include a lubricant. Thelubricant may be a lubricant suitable for use with a refrigeration,air-conditioning, or heat pump apparatus. Lubricants include thoseconventionally used in compression refrigeration apparatus utilizingchlorofluorocarbon refrigerants. Such lubricants and their propertiesare discussed in the 1990 ASHRAE Handbook, Refrigeration Systems andApplications, chapter 8, titled “Lubricants in Refrigeration Systems”,pages 8.1 through 8.21. Lubricants may include those commonly known as“mineral oils” in the field of compression refrigeration lubrication.Mineral oils may include paraffins (i.e. straight-chain andbranched-carbon-chain, saturated hydrocarbons), naphthenes (i.e. cyclicparaffins) and aromatics (i.e. unsaturated, cyclic hydrocarbonscontaining one or more rings characterized by alternating double bonds).Lubricants may include those commonly known as “synthetic oils” in thefield of compression refrigeration lubrication. Synthetic oils mayinclude alkylaryls (i.e. linear and branched alkyl alkylbenzenes),synthetic paraffins and naphthenes, and poly(alphaolefins).Representative conventional lubricants may include the commerciallyavailable BVM 100 N (paraffinic mineral oil sold by BVA Oils), Suniso®3GS and Suniso® 5GS (naphthenic mineral oil sold by Crompton Co.),Sontex® 372LT (naphthenic mineral oil sold by Pennzoil), Calumet® RO-30(naphthenic mineral oil sold by Calumet Lubricants), Zerol® 75, Zerol®150 and Zerol® 500 (linear alkylbenzenes sold by Shrieve Chemicals) andHAB 22 (branched alkylbenzene sold by Nippon Oil).

Lubricants may include those that have been designed for use withhydrofluorocarbon refrigerants and are miscible with refrigerantcompositions described herein under compression refrigeration,air-conditioning, or heat pump apparatus' operating conditions. Suchlubricants and their properties are discussed in “Synthetic Lubricantsand High-Performance Fluids”, R. L. Shubkin, editor, Marcel Dekker,1993. Such lubricants include, but are not limited to, polyol esters(POEs) such as Castrol® 100 (Castrol, United Kingdom), polyalkyleneglycols (PAGs) such as RL-488A from Dow (Dow Chemical, Midland, Mich.),and polyvinyl ethers (PVEs). These lubricants are readily available fromvarious commercial sources.

Lubricants may be selected by considering a given compressor'srequirements and the environment to which the lubricant will be exposed.In some embodiments, lubricants may have a kinematic viscosity of atleast about 5 cs (centistokes) at 40° C.

Commonly used refrigeration system additives may optionally be added, asdesired, to the refrigerant compositions in order to enhance lubricityand system stability. These additives are generally known within thefield of refrigeration compressor lubrication, and include anti-wearagents, extreme pressure lubricants, corrosion and oxidation inhibitors,metal surface deactivators, free radical scavengers, foaming andantifoam control agents, leak detectants and the like. In general, theseadditives are present only in small amounts relative to the overalllubricant composition. They are typically used at concentrations of fromless than about 0.1% to as much as about 3% of each additive. Theseadditives are selected on the basis of the individual systemrequirements. Some typical examples of such additives may include, butare not limited to, lubrication enhancing additives, such as alkyl oraryl esters of phosphoric acid and of thiophosphates. Additionally, themetal dialkyl dithiophosphates (e.g. zinc dialkyl dithiophosphate orZDDP, Lubrizol 1375) and other members of this family of chemicals maybe used in compositions of the present invention. Other anti-wearadditives include natural product oils and asymmetrical polyhydroxyllubrication additives such as Synergol TMS (International Lubricants).Similarly, stabilizers such as antioxidants, free radical scavengers,and water scavengers may be employed. Compounds in this category caninclude, but are not limited to, butylated hydroxy toluene (BHT) andepoxides.

The refrigerant compositions may further include one or more tracersselected from the group including hydrofluorocarbons (HFCs), deuteratedhydrocarbons, deuterated hydrofluorocarbons, perfluorocarbons,fluoroethers, brominated compounds, iodated compounds, alcohols,aldehydes, ketones, nitrous oxide (N2O) and combinations thereof. Thetracer compounds are added to the refrigerant compositions in previouslydetermined quantities to allow detection of any dilution, contaminationor other alteration of the composition, as described in U.S. Pat. No.7,641,809, which is incorporated by reference in its entirety. Singletracer compounds may be used in combination with a refrigeration/heatingfluid in the refrigerant compositions or multiple tracer compounds maybe combined in any proportion to serve as a tracer blend. The tracerblend may contain multiple tracer compounds from the same class ofcompounds or multiple tracer compounds from different classes ofcompounds. For example, a tracer blend may contain two or moredeuterated hydrofluorocarbons, or one deuterated hydrofluorocarbon incombination with one or more perfluorocarbons.

The refrigerant compositions may further include an ultra-violet (UV)dye and optionally a solubilizing agent. The UV dye is a usefulcomponent for detecting leaks of the composition by permitting one toobserve the fluorescence of the dye in the composition at a leak pointor in the vicinity of refrigeration, air-conditioning, or heat pumpapparatus. One may observe the fluorescence of the dye under anultra-violet light. Solubilizing agents may be needed due to poorsolubility of such UV dyes in some compositions.

By “ultra-violet” dye is meant a UV fluorescent composition that absorbslight in the ultra-violet or “near” ultra-violet region of theelectromagnetic spectrum. The fluorescence produced by the UVfluorescent dye under illumination by a UV light that emits radiationwith wavelength from 10 nanometers to 750 nanometers may be detected.Therefore, if a composition containing such a UV fluorescent dye isleaking from a given point in a refrigeration, air-conditioning, or heatpump apparatus, the fluorescence can be detected at the leak point. SuchUV fluorescent dyes include but are not limited to naphthalimides,perylenes, coumarins, anthracenes, phenanthracenes, xanthenes,thioxanthenes, naphthoxanthenes, fluoresceins, and derivatives orcombinations thereof.

Solubilizing agents may include at least one compound selected from thegroup including hydrocarbons, hydrocarbon ethers, dimethylether,polyoxyalkylene glycol ethers, amides, nitriles, ketones, chlorocarbons,esters, lactones, aryl ethers, fluoroethers and 1,1,1-trifluoroalkanes.The polyoxyalkylene glycol ethers, amides, nitriles, ketones,chlorocarbons, esters, lactones, aryl ethers, fluoroethers and1,1,1-trifluoroalkanes solubilizing agents are defined herein as beingcompatibilizers for use with conventional refrigeration lubricants.

Hydrocarbon solubilizing agents may include hydrocarbons includingstraight chained, branched chain or cyclic alkanes or alkenes containingfive or fewer carbon atoms and only hydrogen with no other functionalgroups. Representative hydrocarbon solubilizing agents include propane,propylene, cyclopropane, n-butane, isobutane, 2-methylbutane andn-pentane. It is appreciated that if the composition contains ahydrocarbon, then the solubilizing agent may not be the samehydrocarbon. Hydrocarbon ether solubilizing agents may include etherscontaining only carbon, hydrogen and oxygen, such as dimethyl ether(DME).

Solubilizing agents may be present as a single compound, or may bepresent as a mixture of more than one solubilizing agent. Mixtures ofsolubilizing agents may contain two solubilizing agents from the sameclass of compounds for example two lactones, or two solubilizing agentsfrom two different classes, such as a lactone and a polyoxyalkyleneglycol ether.

Solubilizing agents such as ketones may have an objectionable odor,which can be masked by addition of an odor masking agent or fragrance.Typical examples of odor masking agents or fragrances may includeEvergreen, Fresh Lemon, Cherry, Cinnamon, Peppermint, Floral or OrangePeel all commercially available, as well as d-limonene and pinene. Suchodor masking agents may be used at concentrations of from about 0.001%to as much as about 15% by weight based on the combined weight of odormasking agent and solubilizing agent.

Vapor-compression refrigeration, air-conditioning, or heat pump systemsinclude an evaporator, a compressor, a condenser, and an expansiondevice. A vapor-compression cycle re-uses refrigerant in multiple stepsproducing a cooling effect in one step and a heating effect in adifferent step. The cycle can be described simply as follows. Liquidrefrigerant enters an evaporator through an expansion device, and theliquid refrigerant boils in the evaporator at a low temperature to forma gas and produce cooling. The low-pressure gas enters a compressorwhere the gas is compressed to raise its pressure and temperature. Thehigher-pressure (compressed) gaseous refrigerant then enters thecondenser in which the refrigerant condenses and discharges its heat tothe environment. The refrigerant returns to the expansion device throughwhich the liquid expands from the higher-pressure level in the condenserto the low-pressure level in the evaporator, thus repeating the cycle.

The embodiments disclosed herein provide a refrigeration,air-conditioning or heat pump apparatus containing a refrigerantcomposition as described herein. In some embodiments, the refrigerationor air-conditioning apparatus may be a mobile apparatus. As used herein,mobile refrigeration apparatus or mobile air-conditioning apparatusrefers to any refrigeration or air-conditioning apparatus incorporatedinto a transportation unit for the road, rail, sea, or air. In addition,apparatuses meant to provide refrigeration or air-conditioning for asystem independent of any moving carrier, known as “intermodal” systems,may also implement the compositions and methods described herein. Suchintermodal systems include “containers” (combined sea/land transport) aswell as “swap bodies” (combined road and rail transport). Thecompositions and methods described herein can be useful for roadtransport refrigerating or air-conditioning apparatus, such asautomobile air-conditioning apparatus or refrigerated road transportequipment.

The refrigerant compositions and method as disclosed herein may also beuseful in stationary air-conditioning and heat pumps, e.g. chillers,high temperature heat pumps, residential and light commercial andcommercial air-conditioning systems. In stationary refrigerationapplications, the refrigerant compositions may be useful in equipmentsuch as domestic refrigerators, ice machines, walk-in and reach-incoolers and freezers, and supermarket systems.

The compositions and methods described herein further relate uses as aheat transfer fluid composition. The method comprises transporting therefrigerant composition from a heat source to a heat sink. Heat transferfluids are utilized to transfer, move or remove heat from one space,location, object or body to a different space, location, object or bodyby radiation, conduction, or convection. A heat transfer fluid mayfunction as a secondary coolant by providing thermal transfer forcooling (or heating) from a remote refrigeration (or heating) system. Insome systems, the heat transfer fluid may remain in a constant statethroughout the transfer process (i.e., not evaporate or condense).Alternatively, evaporative cooling processes may utilize heat transferfluids as well.

A heat source may be defined as any space, location, object or body fromwhich it is desirable to transfer, move or remove heat. Examples of heatsources may be spaces (open or enclosed) requiring refrigeration orcooling, such as refrigerator or freezer cases in a supermarket,building spaces requiring air-conditioning, or the passenger compartmentof an automobile requiring air-conditioning. A heat sink may be definedas any space, location, object or body capable of absorbing heat. Avapor compression refrigeration system is one example of such a heatsink.

U.S. Pat. No. 7,914,698 is incorporated by reference herein in itsentirety.

The compositions and methods can be applied to various equipment andcontrols of HVAC systems, including for example chillers including themotors and various compressor types thereof, electronics cooling,bearings, air handlers, purges, evaporators and condensers and the fluidmanagement therein. The compositions and methods can be applied to suchequipment in the retrofitting and servicing thereof, as well as in theflammability detection and prevention including sensors and methods ofventilation to reduce the probability of flammable mixtures.

The following respective US patents and US patent applicationpublications illustrate and describe such equipment, controls, and thelike with which the compositions and methods herein may be used, and areincorporated by reference in their entirety: US20110100051A1, U.S. Pat.No. 8,613,555B2, US20140360210A1, US20150260441A1, U.rS. Pat. Nos.7,421,855B2, 8,011,196B2, 8,627,680B2, 7,856,834B2, 4,223,537A,4,220,011A, US20150034284A1, US20150276282A1, U.S. Pat. Nos.8,132,420B2, 9,032,754B2, 9,032,753B2, US20140224460A1, US20130075069A1,US20150192371A1, US20150276287A1, US20130283832A1, US20130283830A1,US20140223936A1, US20140102665A1, US20150030490A1, US20150030489A1, U.S.Pat. Nos. 9,022,760B2, 8,875,530B2, 8,454,334B2, 7,819,644B2,US20150093273A1, US20150037186A1, US20150037192A1, US20150037184A1, U.S.Pat. No. 7,556,482B2, US20150247658A1, US20110146317A.

Aspects

-   -   Any one or more of aspects 1 to 10 may be combined with any one        or more of aspects 11 to 20. Any one or more of aspects 11 to 13        may be combined with any one or more of aspects 14 to 20. Aspect        14 may be combined with any one or more of aspects 15 to 20.        Aspect 15 may be combined with any one or more of aspects 16        to 20. Aspect 16 may be combined with any one or more of aspects        17 to 20. Aspect 17 may be combined with any one or more of        aspects 18 to 20. Aspect 18 may be combined with any one or more        of aspects 19 and 20. Aspect 19 may be combined with aspect 20.    -   1. A method of reducing flammability of a refrigerant        composition in an HVAC system comprising:        -   adding a first refrigerant into the composition;        -   adding a second refrigerant into the composition; and        -   adding an amount of R125 refrigerant into the composition,            the R125 refrigerant is relatively less flammable than the            first refrigerant and the second refrigerant.    -   2. The method of aspect 1, wherein the first refrigerant is R32        refrigerant and the second refrigerant is R1234yf refrigerant.    -   3. The method of aspect 2, wherein the percentage by weight of        the R32 refrigerant, the R125 refrigerant, and the R1234yf        refrigerant respectively ranges from 64.0 to 69.0, from 6.5 to        7.5, and from 25.5 to 28.5.    -   4. The method of any one of aspects 1 to 3, wherein the amount        of R125 refrigerant ranges from 5.5 percent by weight to 7.5        percent by weight.    -   5. The method of any one of aspects 1 to 4, wherein the amount        of R125 is such that the global warming potential (GWP) of the        refrigerant composition is below the GWP of R32 refrigerant.    -   6. The method of any one of aspects 1 to 5, wherein the        refrigerant composition has a GWP of 675 or less.    -   7. The method of any one of aspects 1 to 6, wherein said adding        the first refrigerant comprises adding a refrigerant with a        relatively high capacity compared to the second refrigerant and        the R125 refrigerant.    -   8. The method of any one of aspects 1 to 7, wherein said adding        the second refrigerant comprises adding a refrigerant with a        relatively low GWP compared to the first refrigerant and the        R125 refrigerant.    -   9. The method of any one of aspects 1 to 8, wherein said adding        the first refrigerant, the second refrigerant, or the R125        refrigerant comprises adding a refrigerant with a relatively        high lubricant solubility compared to the other two        refrigerants, and adding a lubricant, the lubricant comprises        POE, PVE, polyester, or a combination thereof, thereby improving        the lubricant solubility in the HVAC system.    -   10. A method of reducing flammability of a refrigerant        composition in an HVAC system comprising:        -   selecting a suitable amount of a non-flammable refrigerant;        -   selecting a suitable amount of one or more refrigerants with            a relatively low GWP compared to the non-flammable            refrigerant, and where the one or more refrigerants is            relatively flammable compared to the non-flammable            refrigerant; and        -   mixing the non-flammable refrigerant and the one or more            refrigerants with a relatively low GWP to obtain a resulting            refrigerant composition, so as to achieve a desired            performance characteristic of the resulting refrigerant            composition in a HVAC system, the performance characteristic            includes one or more thermodynamic properties of coefficient            of performance (COP), capacity (CAP), a discharge            temperature (Tdisch), or a combination thereof.    -   11. A method of retrofitting a refrigerant composition in an        HVAC system comprising:        -   adding an amount of R125 refrigerant to a flammable            refrigerant composition.    -   12. The method of aspect 11, wherein the flammable refrigerant        is one of a refrigerant blend of R32 refrigerant and R1234yf        refrigerant respectively having a percentage by weight of 72.5        and 27.5, a refrigerant blend of R32 refrigerant and R1234yf        refrigerant respectively having a percentage by weight of 68.9        and 31.1, or a refrigerant blend of R32 refrigerant and R1234yf        refrigerant respectively having a percentage by weight of 36 and        64.    -   13. The method of aspect 11 or 12, further comprising replacing        an existing flammable refrigerant composition of the HVAC system        with the composition resulting from adding the amount of R125        refrigerant to the flammable refrigerant composition.    -   14. A method of servicing an HVAC system comprising:    -   adding an amount of R125 refrigerant to a flammable refrigerant        composition.    -   15. A method of improving safety in an HVAC system comprising:    -   adding an amount of R125 refrigerant to a flammable refrigerant        composition.    -   16. An HVAC system comprising an operational refrigerant        composition, the refrigerant composition includes R32        refrigerant, R125 refrigerant, and R1234yf refrigerant, the        percentage by weight of the R32 refrigerant, the R125        refrigerant, and the R1234yf refrigerant respectively ranges        from 64.0 to 69.0, from 6.5 to 7.5, and from 25.5 to 28.5.    -   17. A method of recycling R410A refrigerant from a HVAC system,        comprising:        -   removing existing R410A refrigerant from the HVAC system;            and        -   adding a refrigerant composition to the HVAC system, the            refrigerant composition including R32 refrigerant, R125            refrigerant, and R1234yf refrigerant, the percentage by            weight of the R32 refrigerant, the R125 refrigerant, and the            R1234yf refrigerant respectively ranges from 64.0 to 69.0,            from 6.5 to 7.5, and from 25.5 to 28.5.    -   18. A method of making a refrigerant composition, comprising:        -   selecting a suitable amount of a first refrigerant to            address flammability of the refrigerant composition,        -   selecting a suitable amount of a second refrigerant to            address GWP of the refrigerant composition;        -   selecting a suitable amount of a third refrigerant to            address capacity of the refrigerant composition; and        -   mixing the first, second, and third refrigerant.    -   19. A method of improving safety of an HVAC system, comprising:        -   selecting a suitable amount of a first refrigerant to            address flammability of the refrigerant composition;        -   selecting a suitable amount of a second refrigerant to            address GWP of the refrigerant composition;        -   selecting a suitable amount of a third refrigerant to            address capacity of the refrigerant composition; and        -   mixing the first, second, and third refrigerant.    -   20. A method of controlling flammability of a refrigerant        composition in an HVAC system, comprising:        -   selecting a suitable amount of a first refrigerant to            address flammability of the refrigerant composition;        -   selecting a suitable amount of a second refrigerant to            address GWP of the refrigerant composition;        -   selecting a suitable amount of a third refrigerant to            address capacity of the refrigerant composition; and        -   mixing the first, second, and third refrigerant.

With regard to the foregoing description, it is to be understood thatchanges may be made in detail, without departing from the scope of thecompositions and methods described herein. It is intended that thespecification and depicted embodiments are to be considered exemplaryonly, with a true scope and spirit of the compositions and methods beingindicated by the broad meaning of the claims.

The invention claimed is:
 1. A method of reducing flammability of arefrigerant composition in a heating, ventilation, and air conditioning(HVAC) system, comprising: adding R32 refrigerant into the composition;adding R1234yf refrigerant into the composition; and adding an amount ofR125 refrigerant into the composition, the R125 refrigerant isrelatively less flammable than the R32 refrigerant and the R1234yfrefrigerant, wherein the amount of R125 refrigerant is 5.5% by weight,6.5% by weight, 7.5% by weight, or from 10.5% to 20% by weight, andwherein the percentage by weight of the R32 refrigerant and the R1234yfrefrigerant respectively ranges from 64.0 to 69.0 and from 25.5 to 28.5.2. The method of claim 1, wherein the amount of the R125 refrigerant issuch that a global warming potential (GWP) of the refrigerantcomposition is below a GWP of the R32 refrigerant.
 3. The method ofclaim 1, wherein the refrigerant composition has a global warmingpotential (GWP) of 675 or less.
 4. The method of claim 1, wherein theR32 refrigerant has a relatively higher capacity than the R1234yfrefrigerant and the R125 refrigerant.
 5. The method of claim 1, whereinthe R1234yf refrigerant has a relatively lower global warming potential(GWP) than the R32 refrigerant and the R125 refrigerant.
 6. The methodof claim 1, wherein the R32 refrigerant, the R1234yf refrigerant, or theR125 refrigerant has a relatively higher lubricant solubility than theother two refrigerants, and adding a lubricant, the lubricant comprisespolyol ester (POE), polyvinyl ether (PVE), polyester, or a combinationthereof.
 7. A method of retrofitting a refrigerant composition in aheating, ventilation, and air conditioning (HVAC) system, comprising:adding an amount of R125 refrigerant to a flammable refrigerantcomposition, wherein the flammable refrigerant is a refrigerant blend ofR32 refrigerant and R1234yf refrigerant respectively having a percentageby weight of 64.0 to 69.0 and 25.5 to 28.5, and wherein the amount ofR125 refrigerant is 5.5% wt, 6.5% wt, 7.5% wt, or 10.5% to 20% wt. 8.The method of claim 7, further comprising replacing an existingflammable refrigerant composition of the HVAC system with thecomposition resulting from adding the amount of R125 refrigerant to theflammable refrigerant composition.
 9. A heating, ventilation, and airconditioning (HVAC) system comprising an operational refrigerantcomposition, the refrigerant composition includes R32 refrigerant, R125refrigerant, and R1234yf refrigerant, the percentage by weight of theR32 refrigerant and the R1234yf refrigerant respectively ranges from64.0 to 69.0 and from 25.5 to 28.5, and the percentage by weight of theR125 refrigerant is 5.5, 6.5, 7.5, or from 10.5 to
 20. 10. A method ofrecycling R410A refrigerant from a heating, ventilation, and airconditioning (HVAC) system, comprising: removing existing R410Arefrigerant from the HVAC system; and adding a refrigerant compositionto the HVAC system, the refrigerant composition including R32refrigerant, R125 refrigerant, and R1234yf refrigerant, the percentageby weight of the R32 refrigerant and the R1234yf refrigerantrespectively ranges from 64.0 to 69.0 and from 25.5 to 28.5, and thepercentage by weight of the R125 refrigerant is 5.5, 6.5, 7.5, or from10.5 to 20.